Process of laying pavements.



Patented August 30, 1904.

Tr ce.

PAT NT AUGUST E. SOHUTTE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TOWVARREN BROTHERS COMPANY OF CHARLESTON, WEST VIRGINIA, A CORPORATION OFWVEST VIRGINIA, OF BOSTON, MASSACHUSETTS.

PROCESS OF LAYING PAVEMENTS.

SPECIFICATION forming part of Letters Patent No. 768,699, dated August30, 1904.

Application filed August 21, 1902. Serial No. 120,576. (No specimens.)

To all whom it near concern.-

ing taken out my first naturalization papersas a citizen of the UnitedStates, residingin Cambridge, in the county of Middlesex and State'ofMassachusetts, have invented a new and useful Process of LayingPavements of That Class Known as Bituminous Macadam, of which thefollowing is a specification.

The bituminous macadam is a pavement now generally well known, andconsists of a mixture of coarse stone and bitumen upon a suitablefoundation. The stony ingredients roughly interlock, and the voids orinterstices between the same contain a bituminous cement or binder forholding the stones in position.

In the manufacture of bituminous macadam pavements or roadways of suchcharacter it is desirable that the binding-cement shall very closelyfill the voids between the stone which forms the body of the roadway. Asa means for accomplishing this result I have devised the followingprocess These roadways are ordinarily laid upon a foundation of somekind. While the foundation forms no part of my present invention and maybe of any desired character, I prefer 'to have such foundation made of alayer of coarse cracked stone coated with a hard bituminous cement whichshall serve as a binder, so that when the foundation is rolled firmly inplace it shall so remain. In making a roadway by my improvement upon afoundation either so or otherwise constructed I laya soft matrix sayfrom one tooneand a half inches thick-preferably produced frombituminous cement, -so called, mixed with fine sand and stone-say fromabout one-fourth of an inch in diameter to the finest dust. This matrixis spread to a thickness in proportion to the thickness of the pavementdesired; Upon this matrix while still hot is placed a layer of thelarger stone of about one and a half inches in diameter, preferablyalready coated with bituminous cement and in a heated condition. Thesestones are then rolled by a heavy roller or otherwise embedded in thematrix, which is caused by the rolling or embedding process to receivethe stone and ooze up between the stones, so that the stone isthoroughly embedded in the matrix. All the voids are thus filled, andperhaps a light coating or surfacing is formed for the roadway. Thiscoating may be sufficient to form the finishing-surface of the roadway.If desired, however, an additional thin finishing-coat of some propercharacterfor example, any one of the finishingcoatings now in use whichwill combine with the matrix and stone surfacingmay 'be laid upon theroadway so constructed.

This process is simple and easy to carry out and forms a firm, hard,.and elastic roadway well fitted for all the ordinary uses of travel.

What I claim as myinvention is 1. That process of making a bituminousmacadam roadway which consists in laying a matrix of the characterdescribed upon a suitable foundation and pressing into it a layer ofcoarse stone whereby said stone will be em bedded in the matrix and thematrix will fill the voids between the stones as described.

2. That improvement in the art of making bituminous macadam roadwayswhich consists in forming a foundation of crushed stone or the like,laying thereon a matrix composed of bituminous cement, sand and smallstone and then embedding in said matrix a layer of coarse stone as setforth.

3. That improvement in the art of making bituminous macadam roadwayswhich consists in laying upon a suitable foundation a matrix composed ofbituminous cement or the like mixed with fine sand and small stone,embedding in said matrix by pressure larger stone whereby said matrixwill be caused to fill the voids between said larger stone, and addingthereto a finishing-coating as and for the purposes described.

4:. That improvement in the art of making bituminous macadam roadwayswhich consists in laying upon a suitable foundation a matrix made fromsmall stone, sand and a bituminous cement and adding thereto a layer ofcoarse stone coated with bituminous cement whi'le hot and embedding saidcoarse stone in said matrix by pressure as and for the purposesdescribed.

5. That process of making a bituminous macadam roadway which consists inlaying a matrix to a predetermined depth upon a suitable foundation thenapplying to the top thereof such a layer of selected stone that uponsubsequent rolling, the stone is forced into the matrix to form abituminous macadam mixture, then applying such pressure on the surfaceas to accomplish the desired results.

6. That process of making a bituminous i'nz'icadan'i roadway Whichconsists in laying a matrix to the depth of about one to one andone-half inches upon a suitable foundation then applying to the top ofsuch matrix a layer of stone of sizes of approximately one and on ehalfinches, and applying such pressure on the surface as to force the stonethrough the matrix.

7. That process of making a bituminous macadam roadway which consists inplacing upon a suitable foundation a layer of matrix, placing upon suchmatrix, coarse uneven stones such as Will interlock With each other uponbeing subjected to pressure, and then pressing such'stones together andinto the matrix, and into closely interlocking relation to each other.

8. That process of making a bituminous macadam roadway Which consists"in placing upon a suitable foundation a layer of matrix substantiallyas described, placing stone upon the surface of such matrix and thenforcing such stones in the matrix and into an interlocking contact Witheach other in such a Way that the matrix fills the voids between thestones.

AUGUST E. SOHUTTE.

Witnesses:

M. D. NEWMAN,

SAUL Srrrnnsrnm.

